hospital talking about the blast. what they heard, what they saw, the desperate search for loved ones in boston. brian? >> i don't know thjonathan hall this all day. a terrible day in the history of boston. we are now joined by dr. ron walls, chief of emergency services at brigham and women's. thank you very much for taking time to talk with us tonight. a couple of things i'm struck by watching the coverage today. number one, how fortunate that if a terrible thing had to happen it happened adjacent to the medical tent. so triage was fast. they were transported quickly and boston is fortunate to have some first class medical facilities close in and nearby. correct? >> yes. that's right. we have worked a lot on drilling these exact kind of events, not just within our level one trauma center here at brigham & women's but city wide. we have done a lot of work

getting ready for something we hoped would never happen. >> sadly, doctor, two aspects of this sounded so familiar to those of us who have been covering combat the past several years, even on a part-time basis. number one, the notion of a primary and then secondary explosion. and number two, the nature of some of these injuries. i understand you have had some full leg amputations and there are shrapnel wounds. >> we had a lot of injuries, particularly to people's legs as they were closer to the blast site. also had a fair number of people injured by flying objects. we didn't see evidence that there were objects built into the device. these were random flying objects sent flying by the explosion of the bomb. or bombs. >> but really, leaving for work this morning on what is a holiday across the city, i am guessing that maybe brigham and women's hospital thought there would be dehydration cases, some after effect of the race.

i'm guessing it is the last thing you thought you would have multiple casualties from a single event in that say. >> certainly hard to see this coming in any way. we fortunately have a medical team we deploy near the finish line anyway just as part of the normal coverage of the event. but we were ready and not ready. we are ready for this because we are ready for this any time. we certainly weren't anticipating the this today. >> dr. ron walls, chief of emergency services at the great brigham and women's hospital in boston, mass. doctor, thank you for your day-long work on behalf of the folks brought to your doorstep. to our justice correspondent we go once again. pete williams in our washington bureau. pete, it probably bears repeating at this point while people may be seeing other aspects of security at their local airport train station, no reason to think this is anything

beyond the boylston street bombings that we saw in boston. >> reporter: that's right. according to the officials i have talked to tonight, brian. of course they are still trying to figure out precisely what it was that happened in boston. we know that there were two bombs, but they are still saying there might have been others planted along the route of the marathon. packages found on the street were deemed suspicious and were being destroyed tonight. we still have not heard any firm confirmation of whether at least the five other packages actually were explosive devices, although some officials say there is reason to think they were. there is no suspect in custody. but people are very interested in questioning a young person with a student visa who has burns and was seen by witnesses running from the area. but no suspects are formally in custody. several officials say the two bombs that did go off included shrapnel to multiply injuries including ball bearings. this unfortunately is not an

innovation and has been used in terror bombings in the past. investigators are studying surveillance video to see if they can see anyone actually placing packages at the point where the bombs went off. they describe the devices as crude with, thankfully, less explosive power than might have been contained in packages of this size. now strictly as a precaution security has been stepped up around the white house to the hotels and places where crowds gather including some airports. a homeland security official says no directives have been sent suggesting higher alert and no reason to think this is anything other than a threat to boston. reminiscent of the olympic park bombing in atlanta in 1996, this was caused by white supremacist eric rudolph. more than a hundred hurt. three years ago a white supremacist planted a backpack

bomb along the parade route for a martin luther king day observance in spokane, washington, but it was discovered before the event and was safely removed, brian. >> pete williams in our washington bureau. pete, thanks. i want to bring in a proud son of boston. former boston police commissioner, new york city and los angeles. these days a security consultant. bill bratton. i understand you are in the london bureau where among the subjects you discussed today was public event security. i.e. prime minister thatcher's funeral where you have 2000 vips attending. how are we going to defend and protect our public events when this goes off within the security cordon apparently surrounded by police, ems, volunteers at the finish line of your beloved boston marathon. >> the reality as was evident

today is you can't protect everything all the time. you try to prioritize, focus. you try to identify if there is a threat. boston police commissioner indicated there had been no threat received by either his department or to his knowledge federal agencies. the fact that homeland security is not advising other areas of the country to raise their terrorism level, terrorism concern level is an indication to this stage there is no credible threat that's been identified prior to the event of this afternoon in boston. >> and commissioner, if you were back here, would it be your guess that they will have one, two, three assorted views of the suspect on surveillance video by the time we go to bed u.s. time tonight? >> my sense is that what's happening at this moment there is they are attempting to, one, interview as many of those

people who were transported to hospitals with injuries. they are trying to basically certainly be identifying and trying to interview all of the public safety personnel who were assigned to that specific area. they wl be attempting to locate and interview people who were in the immediate area who were not injured but who may have seen things going on. they will certainly be looking at whatever cameras are in that area. that area has a bank on the corner with a number of businesses. so the common practice now is to try to identify what cameras are in that area and to retrieve whatever film they may have. the irony here is two hours before this event that would have been one of the most heavily photographed areas in the world because there were hundreds of cameras from all over the world to record the finish of the marathon. this event occurred almost two hours after the first runner and female runner came across the finish line. so it was fortunate in some respects that the device went

off two hours after the end of the race, if you will, the front runner. otherwise it would have been much larger crowds in the area at that time. >> i talked to a woman who said she was in a restaurant just out of the blast zone. they came in. boston p.d. said everyone with a cell phone put it down. was that because they were worried about an accidental ignition of a bomb? was that because they were fearful that maybe someone who was setting off the devices was in the restaurant? >> you know, brian, i'm going to have to process ignorance about that set of instructions. whether the concern was by the police officers acting on their own that a device oh might have been remotely set off with a cell phone or if there was a concern that cell phone usage might accidentally set off a other as yet unexploded devices. you had a report earlier that as many as five items had been destroyed by the police as a

note of caution. they might have contained explosive devices. that particular instruction. i can't help you out on what might have prompted that. >> commissioner bill bratton, thank you very much for being with us from our london bureau. >> thank you. back to the white house we go. chuck todd is out on the white house lawn. chuck, i have just been told house speaker boehner is leading a moment of oh silence for the boston victims across town from you on the floor of congress. >> reporter: he is. we now see flags are officially being lowered to half staff. the president himself has been really in information receive mode. he's been getting updates all day when it comes from his homeland security director, fbi director. it's what the president said and what he didn't say that's important to listen to. take a listen to what the president said about who could be behind this and what will happen when they figure it out.

>> we still do not know who did this or why. and people shouldn't jump to conclusions before we have all the facts. but make no mistake. we will get to the bottom of this. we will find out who did this. we'll find out why they did this. any responsible individuals, any responsible groups will feel the full weight of justice. >> reporter: as you heard there he specifically didn't say the word "terrorism." that was a decision they made in advance not to use that term. down the street, brian, as you know, the president himself has briefed congressional leaders and speaker boehner himself led the u.s. congress in a moment of silence for those victims in boston. we are showing you a little bit of that now. so, brian, all of washington a little bit on edge because of a frustration of how little they seem to know which is unusual for this town.

>> and, chuck, another illustration of the dark days that can come to the president. whoever happens to be the president at any given time. last time we saw the president kind of in this cast was days before christmas, that terribly sad announcement after newtown. >> reporter: it was. you know, it's interesting the different tone. you could hear and feel the frustration with the president this time. in the newtown days and just how much of a gut punch. you could see the emotion with the president there. here, you can see and feel and hear the determination and, frankly, the frustration in his voice about the lack of what they know about what happened, who did this, and why. i can tell you in talking with various security officials they are frustrated. they are not used to even four hours after something like this happens to know as little as they seem to know tonight. >> chuck todd on the white house north lawn for us tonight. chuck, thanks.

we'll take a break. our coverage will continue right after this.

we are back tonight with our continuing coverage of this awful thing that has happened on what is usually a joyous and sparkling day in the city of boston, mass. for more on that, we want to talk with veteran sports columnist for the new york daily news, author and broadcaster mike lupica. mike, you and i spoke earlier right after the news and right after the import of what happened here sunk in. for people not familiar with patriots day in boston, with this race as an event, what should they know about what this day should be like? >> reporter: brian, people talk about it as a state holiday.

boston on this day and particularly this area around the finish line, it's like the capital of happy people. the only thing i have been comparing it to -- it's a beautiful day that's like times square on new year's eve in new york city. what's not supposed to happen is you are not supposed to see people running in terror away from the finish line. this is the day when you make it to the finish line and you are cheerelike the biggest winner in the world whether it took you three hours, four or five hours. i just talked -- my son is a junior at boston college, as you know. his sister -- the roommate of his sister ran in the race. a lot of the kids carry phones, some to listen to music. she's at the 23-mile mark today and her brother is at the finish line across the street from where the first bomb hit saying, stop running, a bomb went off here. >> think about the perversion of

that. the fact that half of the race was still snaked through the streets, full stop. their day is over. all the achievement, all the struggle and challenge that went into this. think about the fact that most runners arrive in boston with a support group of two or three people. it is supposed to feel like new year's eve in new york only during the day. all of that comes to an end. >> and just up boylston street is the public garden and boston commons which is the central park of boston. again, that is always a joyful place on this day. it became the saddest collection area for families and friends of runners on this day that there's ever been -- brian, there have been times in the past, i can't tell you how many times i have covered this race. again, it's a celebration, not just of the race, but of being alive in boston. when you try to make your way from fenway park from the baseball game back to the finish line you sometimes feel like you have run a marathon yourself.

but all you see are smiling people and now you balance that off against the pictures that you have been showing for the last several hours. >> mike lupica, thank you so much for being with us. some great words after an awful day in a great american city. mike lupica of the new york daily news. back with more of the other news of this day right after this. [ female announcer ] safeway presents

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we are back. we'll have more on this situation in boston in a moment. first we wanted to get you caught up on the day's other news including what had been our top story all day until word arrived from boston. that, of course, is the situation in north korea. it remains tense tonight. still no missile launch from there though one was widely

expected today on what would have been the 101st birthday of the founder of the nation, kim il song. the current owner kim jong un was seen in public today for the first time in two weeks, paying respects at the grave site of his grandfather. secretary of state john kerry is back in this country tonight after a whirlwind round of diplomacy in the region trying among other things to pressure china to put pressure on its ally north korea to back down from its nuclear threats. in venezuela, hugo chavez's chosen successor, the interim president nicholas maduro has been elected that nation's new president. a narrow win though. just over 50% of the vote. and in this country the f.a.a. has ordered more than a thousand, mostly late model boeing 737s to be examined to see if a part of the planes'

tails need to be replaced. specifically it's a pin that holds the horizontal stabilizer which the pilots use to control the pitch of the aircraft. the potential defect has not caused any accidents. f.a.a. says there is no immediate threat. if that were the case they say the planes would all be grounded and nothing close to that is happening. we're back with more of our coverage of the attack today in boston right after this.

we are back and back up to boston we go. nbc's katy tur was able to make her way up there after first word of this. it was striking to hear the governor of massachusetts tell people to stay in their homes, stay off the streets and avoid

crowds. i imagine the center of the city still feels so eerie. >> so eerie, brian. everything that was dropped along the race route now is being considered suspicious. so they didn't want anybody around potentially dropping anything else or potentially getting in the way. they didn't know if other devices were out there at this time. people are looking for answers. right now there are still so few. what we can tell you is that the homeland security chairman has called this terrorism. this was not an accident. it was intentional. it was intended to hurt and it was intended to scare, he says. it has done just that. it happened right around the four-hour mark of the race intended, it seems to do as much damage as possible. that's when most people finish the race. the back bay is silent. people are wondering what's going on. of course they are trying to figure out why anyone would do this. >> katy tur in boston where today was supposed to be just patriots day, a statewide

holiday and just known for the running of the boston marathon. we are back at 10:00 p.m. eastern, 7:00 on the west coast. a special report on oh what happened today in boston.

with breaking news. right now 6:30. three people dead including an 8 year old and dozens more are injured. trying to get in touch with their loved ones. thanks for joining us.

i'm raj mathai. >> and i'm jessica aguirre. the fbi has taken over this investigation. >> this is impacting athletes and families from across the world including right here in the bay area. you see the multiple cameras capturing the explosion from several angles. this is the heart of boston literally and figuratively. >> cheryl hurd is at the oakland coliseum where security has been increased. tony kovaleski has the latest on the investigation but we begin with scott budman who has been in touch with several of the bay area runners and has participated in the day's race. >> absolutely. there were several bay area runners represented. we spoke to a few of them after the explosion and they told us stories of chaos. >> reporter: it was a

frightening scene of confusion and several cross the finish line before the explosion it went from one of accomplishment to chaos. >> maybe 20 seconds away and i'm passing this explosion and like 20 seconds later there was a bigger explosion. i turned around to look at that and it was on the same side of the street but bigger. and people all of a sudden people were yelling at us. >> telling people to clear out, get out of there. >> and so in the street people started moving out very quickly. and then just the sirens. >> reporter: after crossing the

finish line tracy christianson and her husband ended up walking several more miles to reach their hotel. they are fine. also running the race, san francisco's colin alley. he, too, crossed the finish line before the explosion and then spent the next several hours calling and texting friends to make sure they were all okay. we spoke to him as his cell phone battery was dwindling. >> definitely. i feel like the mood in the city changed. i'm happy that i'm okay, of course. i'm happy that all of those that i know that travelled here are okay. it is still one of those things that is saddening and disheartening about our society. >> reporter: he said he felt great when he crossed the finish line. shortly afterward all he felt was sadness.

>> lots of people from here in the bay area hopping on google tonight have the people finder set up to help track down those in boston that they are looking for. >> president obama addressed the nation shortly after 3:00 this afternoon our time. as we just noted the fbi is running this investigation and the president says the full federal government will be used to find the person responsible for this attack. we have more from chief investigative reporter tony kovaleski. i know you spend the day talking to your federal law enforcement sources across the country. >> we are hearing there was no active specific target in california that is receiving special attention but everyone stresses that all agencies remain on high alert status. one of the early keys is the fact that they did recover at least one device that did not detonate. that is key because they are skilled at reverse engineering

these devices. we are told the sophistication will help determine the potential suspect or suspects. you can bet they are combing through every piece of video and video cameras in that area. federal agents are currently running down leads internationally and domestically and two sources said today is also tax day. we also confirmed there is no individual or individuals from the bay area currently being investigated for any connection to the boston bombing. and finally two sources say on attacks like this it is not uncommon to have what is called a spike in monitored chatter and communications. both sources said according to federal agents the federal agents did not see spike in chatter before today's bombing. we have been in contact with senator dianne feinstein who chaired the senate intelligence

committee. she told us she has been briefed on the situation and intelligence officials told her they have no advanced warnings and this has the hallmarks of terrorism. law enforcement officials are on heightened alert. thousands of sports fans are on their way to oakland. nbc bay area's cheryl hurd joins us at the coliseum where at 35,000 fans will be greeted with heavy security in the next hour. >> reporter: two major sporting events here. one here at the oracle arena, the other here at the oakland as. authorities say they are concerned about safety every time there is a sporting event here but they are on heightened alert because of what happened in boston. there is increased police presence on all bart trains. today's fatal explosion has passengers on high alert.

>> to travel these days you have to be careful because you never know what is going to happen. you have to really be careful. >> reporter: officials are ramping up security at facilities throughout the system, as well. public safety operators are being asked to be vigilant and aware of their surroundings following the boston incident. >> nothing trumps public safety in our city. >> reporter: san francisco mayor and his command staff laying out the plans for increased security in san francisco. >> it is premature for us to second guess what we may have to do. we may have to do it with a levelled intelligence and in from federal entities. >> reporter: san francisco is getting ready to host a race of its own next month. it attracts hundreds of thousands of people from all over the world. the top says it is too soon to come to a conclusion. mayor lee wants the public to

know safety is the number one priority in his city. >> anything happening anywhere in the world or in the country we have protocols that we introduced immediately. all of the officers from the san francisco police department are assigned a uniform and put out on the street. >> across the bay in oakland there are two sporting events tonight. police chief says his department is working with with stadium officials on security. >> one of the things taking place here since we realize this event here at oakland is working with the u.s. coast guard and bomb squad to conduct sweeps of the facilities right now. so all of those areas are being checked. they will be continuously checked along with my staff and the staff from the agencies will remain on hand. hopefully we will not need them. >> reporter: chief said tonight he doesn't want the public to be

so concerned about safety that they stay home. he says he wants people to come out and enjoy themselves. he is asking the public to be vigilant. he says if you see something say something. in oakland cheryl hurd. the federal aviation administration stopped air traffic at boston's loegal international airport for about one hour. that delay impacted flights nationwide. the video that you are looking at is at sfo. officers are looking through trash bins. passengers say it is reassuring. >> we saw the police dogs and the guy on the motorized beam walking around and police men standing there making their presence known which is good. it is a little relief. >> police are staying visible at all three local airports tonight.

however an airport spokesperson says none of the local airports have changed their security levels. as we noted earlier today's marathon included dozens of bay area runners. the mayor of boston has set up a hotline. 617-635-4700. we would like you to stay with nbc bay area for continuing coverage of the boston explosions on air and online. you can visit our website, nbcbayarea.com you can find more raw video and photos. we will continue to update you on the latest developments throughout this newscast. a life saving stroke of love. ahead at 6:00, the freak accident leads to a dramatic rescue on a local baseball field. >> what's wrong? you need to tell me. and she just said i can't do that. also, parents taking action. an emotional day in the south bay as the parents of audrie pott are speaking out for the first time.

and the fbi is asking for your help, the connection to an infamous killer in the bay area. we have been watching a blustery day. peak wind gusts. the hill tops above 50 miles per hour. we are watching the wind advisory for this evening. showers not too far away. we will let you know if any of that is heading your way. we'll have a look when we come right back.

they're fighting through their pain and loss in hopes of helping other families. today the family of audrie pott opened up about their 15-year-old daughter who committed suicide following an alleged sexual assault. >> the family filed a wrongful

death lawsuit. we have team coverage for you this evening. kris sanchez begins coverage with more on the civil lawsuit. are there criminal cases at this point. >> reporter: in that civil lawsuit that was filed this afternoon it says that when audrie pott woke up after a night of drinking at that home in saratoga last labor day her shorts were off and there were words and drawings all over her body. those were messages that her family ultimately drove her to suicide. >> she warmed the room with her smile and made us laugh at her incredible wit. >> reporter: her mother said that changed after drinking at a friend's house she lost consciousness and was allegedly sexual assaulted by three

16-year-old boys. the boys sent photos and sent them to friends. weeks later audrie took her own life. >> i asked repeatedly, what's wrong? you need to tell me. she just said i can't do that. >> reporter: the pott family believed the assault and passing of photographs is the reason their daughter took her own life and say that is why they filed a wrongful death lawsuit against the suspects today. >> she is missed every day. >> reporter: her step mother read some of the messages she says audrie posted on the facebook page. >> i don't want to remember. it's a night i want to forget. i'm in hell. everyone knows about that night. the whole school is talking about it.

my life is over. >> reporter: the family attorney says he hopes the photos of the attack will help persuade prosecutors to try those 16-year-old boys as adults. >> one marking said the name of a young man was here as if to taunt her when she was asleep someone was violating her. that is a factor that is indicative to the intent that was formed to really do harm to her. >> reporter: now, michael and sheila of saratoga were named in the lawsuit. they own the home where the alleged assault happen. the three 16-year-old boys remain in custody at juvenile detention behind me and they will face a judge to find out if they will be released to their families. the parents are hoping the prosecutors will charge them as adults with felony sexual assault. kris sanchez, nbc bay area news.

emotionally it is a difficult story. legally it is complex. should the three teenage boys be tried as adults? what are the options? what happens next? >> reporter: in some cases the district attorney doesn't have to decide it automatically charges juveniles as adults. those cases, though, usually have to do with some type of murder. most of the time the d.a. relies on a statute called 707-b. the state of california outlines 30 serious or violent crimes that allows prosecutors to automatically charge juveniles as adults. the district attorney's office can make a direct filing or call for a hearing to see if the minor should be tried as a juvenile or an adult. what happens if a minor commits

a crime that are serious. >> some crimes are sexual assault when they are unconscious or intoxicated, something of that nature. >> reporter: for the juvenile commits a crime not on the list that juvenile can be charged as an adult. >> the crime isn't a 707 b crime. we take it very seriously. if a person or minor were to commit a string of those crimes or one of those crimes we could deem it that they be prosecuted as an adult. >> reporter: in the case of audrie pott a lot of people are urging the d.a.'s office to charge the suspects as adults. the district attorney's office is prohibited by law from commenting on the case specifically but the d.a. does take into consideration the victim, the seriousness and sophistication and if the juvenile would be a danger in the future.

>> it is our job to analyze the law and the facts and make the appropriate decision to make sure that this person would be held accountable. >> reporter: now, in juvenile court cases are confidential meaning there are no open hearings or identify said suspects. if they turn into a 707 b case then that information becomes part of the public record. oakland police are looking for a man suspected of molesting a girl after he got into a family's apartment after posing as a maintenance worker. an adult let the suspect in and he ran off as the 10-year-old started screaming. police are describing the suspect as a caucasian man in hiss with brown hair and a gray beard. he has paint stains in his hair.

there is a $5,000 reward being offered for information leading to his arrest. the fbi is still trying to identify his victims. agents say before anderson died of liver failure he admitted to eight killings, two of them were seven year old bay area girls. tonight the tv series "fbi criminal pursuit" will air a documentary about anderson including his description of other murders including women he met in bars. those women are still unidentified. urgent changes are needed to prevent another explosion like the one at chevron's refinery last year. this morning the federal agency released its much anticipated

report that says chevron knew about possible corrosion of that pipe that failed for ten years but did nothing to replace it. despite their own team's recommendation to do so. the chemical safety board says tougher regulations are needed to require oil companies to make sheez fixes. chevron has ways to know the risk. however, there was no effective intervention before the major accident occurred. >> chevron says it is reviewing the report and its recommendations but notes it is already taking steps to improve safety. it is going to be a hassle for south bay drivers. construction on the bart expansion is underway. work began today in north san jose. crews are taking up the median. you can expect lots of lane shifts and traffic delays. the project is meant to pave the

way for bart trains to move in underground. the crews will be working from 7:00 in the morning until 7:00 at night, six days a week. they say they are going to try to disturb traffic at little as possible but it is going to be a little difficult. the bart extension is expected to be completed by 2018. let's bring in rob. >> gusts about 60 miles per hour. you are seeing the reason why in the map behind me. we have the wind advisory up to the bay area coast line, inner bay and north bay hill top until 9:00 this evening. we have seen the strongest winds and wind speeds will try to subside. temperatures this is the case of canadian air conditioning. low to mid 50s out there. off to the east showers out by

sacramento. notice here in the future cast hour by hour almeida county east of san jose slight risk of a shower but most activity moves to the east. this is cool air dropping in out of the north. high pressure builds back towards california we are going to see a little less wind tomorrow. slightly warmer temperatures but the real warmup comes wednesday into thursday. the high to our north and east. offshore breezes. temperatures rising up, 70s and 80s. wind protected valleys could get chilly down towards gilroy. numbers in the upper 30s. you'll want a coat as you head off to work and school. highs a little warmer. 60s for most of the bay area. 70 in pleasanton. 64 in san francisco. 70 in santa rosa. from here a little less wind as we go into tuesday, wednesday and beyond. inland valleys in the 70s and

80s and offshore breezes out to the coast should be pleasant. we should see numbers closer to 70 as we approach the weekend and head into the start of next week. up next paramedics in the right place at the right time. the freak accident that nearly cost a local little leaguer his life. we're back in a moment. look at them kids. [ sigh ]

they have no idea what it was like before u-verse high speed internet. yeah, you couldn't just stream movies to a device like that. one time, i had to wait half a day to watch a movie. you watched movies?! i was lucky if i could watch a show. show?! man, i was happy to see a sneezing panda clip! trevor, have you eaten today? you sound a little grumpy. [ laughter ] [ male announcer ] connect all your wi-fi-enabled devices with u-verse high speed internet. rethink possible.

local little league officials say two angels are responsible for saving the life of an 8-year-old who went into cardiac arrest. witnesses say the boy got a base hit and went to first base and collapsed. two of the off duty paramedics

>> the parents did cpr for approximately five minutes and then the department of public safety showed up with a defib rulater and his heart started beating again. he began crying and was loaded into an ambulance and taken to santa rosa memorial hospital. >> this was in the north bay. the boy could be released as early as tomorrow. >> such a relief for that family. thank you so much for watching this special edition. there is an nbc news special report on boston coming up. we will be back with a special 90 minute late newscast. on our morning newscast terry mcsweeney will be live in boston with the latest on the investigation. one more note here tonight. after running more than 26 miles and hearing about the explosion in boston several runners today in boston at the marathon kept

running straight to massachusetts general hospital so they could give blood, a glimmer of light on this otherwise dark day. >> we will leave you with a shot of the flags at the capitol.

tonight, a nbc news special report. after an awful day in boston, a bombing at the finish line of the boston marathon. there are mass casualties including children.

the latest on what happened and where the investigation stands and including a search for a suspect as our nbc news special report gets under way. good evening. it is the best day every year in boston. the running of the boston marathon. it's a holiday, patriots day. the kids are home from school. the rocks play at fenway park today and they won and started off as a great day in boston. then, all eyes turned to the finish line at the marathon. at 2:50 this afternoon, 4:09 in to the race, what the "the boston globe" recorded at ground level. a sudden blast in front of spectators, volunteers and police officers. then seconds later, a second blast. and the remnants of the scene suddenly show a mass casualty event. tonight, the death toll stands at three, including an 8-year-old. over 100 others were treetded for injuries. the race was stopped mid route.

thousands of people pushed through the streets as the streets were closed off behind them. bostonians were told not to come out, stay in their homes and avoid crowds and the investigation began immediately while security was heightened across the country. we begin tonight with the latest on this day from nbc's dennis murphy. >> reporter: a sharp bang, then seconds later, two blocks away -- another explosion. a plume of thick, gray smoke spiraled up over boylston street marking the two spots virtually the finish line where who knew what had just happened. >> multiple people down here. okay? i don't know what the cause is. stand by. >> reporter: but whatever it was, a great many people have suffered ghastly injuries. both runners and spectators cheering on the back of the pack finishers four hours after the start of the marathon.